Wearable devices, in particular wristwatches, fitted with a thermometer have been proposed, since display of the ambient temperature is useful information appreciated by many users. In general, the temperature sensors used are resistive-type sensors or are formed by a thermocouple. Such sensors indicate the temperature of their direct surroundings. In the case of a wristwatch in particular, it is the temperature prevailing in the watch case that is measured when the thermometer is arranged in this case. However, the human body is a source of energy that generally has a substantial influence on the temperature inside the case when the wristwatch is worn on the wrist. Hence, it is difficult, if not impossible, to measure the ambient temperature precisely when the wristwatch is worn on the wrist. In fact, it must be removed and placed on a non-heating support, and then it is necessary to wait a relatively long period of time until the temperature of the watch is close to ambient temperature to finally perform a measurement of the ambient temperature. This situation is highly inconvenient for the user, which makes this temperature measurement function of little appeal in a wearable object, in particular in a watch. Some configurations seek to move the sensor the maximum distance away from the wrist and/or to thermally insulate it from parts in direct contact with the human body. However, these solutions are technically complex and difficult to implement in a wristwatch.